Honing machine



3 Sheets-Sheet l HoNING MACHINE Filed July 8, 1956 A Q M. JOHNSON m .w W w sept. 20,' 193s. A. M. JOHNSQN 2,130,393

HoNING MACHINE' Filed July 8, 1936 5 Sheets-Sheet 2 werf @MV Sept. 20, 1938. A. M. JOHNSON HONING MACHINE Filed July s, 1936 3 Sheets-Sheet 3 Ww w etented Sent. 2G, i938 anche HGNNG MAKCMNE alba-r ra lenssen, ammore, nl., assigner to es Brill Co., Rcchlcrd, lill., a corporation ol minets 'Application .lilly d, i935, Seriabho. 9,561

2li Claims.

fore constructed, the tool carrying spindle is jour- A naled in a reciprocatory head or carriage supported and guided by Ways on the frame of the machine. Reciprocation of the tool spindle is effected by reciprocating the spindle head by means of a hydraulic cylinder and piston mechanism which ordinarily has one orvmore. operating cylinders mounted on the frame and the piston or pistons rigidly secured to the head. For rotating the spindle, there is a drive shaft usually rotatably anchored in the head and reciprocable therewith, a gear train in the head drivingly connecting the shaft and spindle. With this construction the Weight of the reciprocating parts is necessarily quite large.

One' of the most important requirements for precision honing is that the tool be reciprocated smoothly and rapidly and With substantially no lag at either end or the stroke. To enable the machine tmeet these requirements and to withstand the shocks and strains imposed bythe relatively large mass of the reciprocating parts, the framework and other elements of the machine must be of exceptionallyy heavy and rigid construction, which, o( course, adds to the cost of .the machine. The construction of the spindle head and the machining ofthe ways, which must j be particularly true andaccurate, also represents a substantia1 item in the cost of building the malchine.

With the foregoing in view, one object of the invention is to provide an improved honing machine in which, by reason of the novel arrangement or the .various elements and the simplified construction thereof, the Weight of the reciprocating parts isreduced to a minimum and the Amachine is rendered. 'capable 'of being manufactrued ata relativelylow cost. The above and Aother objects are attained through the provision of ax, honing machine in which the spindle carriageiis dispensed with entirely, the spindle itself extending' into and through fthe operating cylinder and carrying the pistonI by which reciprocation is eected.

Another object is to provide an improved honing machine having a hydraulically reciprocated hone and'embodying means ci an advantageous (El. 51m-34) character for positively limiting the Working stroke of the hone to edectually prevent overrun at either end of the stroke. l

Another object is to provide an improved control mechanism for controlling the reciprocation o the honing tool, which mechanism is of simple and rugged construction and which is capable of extremely accurate adjustment.

Still another object is to provide an improved electrical control system for a honing machine whereby the various operationeel the machine may be controlled through the medium of conveniently located push buttons.

A further object is to provide improved short stroking means by which the operative eiiect of the honing tool may be concentrated at selected areas on the work to remove high spots, taper, or the like.

Y Further objects and advantages will be apparent from the following detailed description of the preferred embodiment selected for illustration in the accompanying drawings. It will be understood, however, that various changes in form, construction and arrangement of the parts may be made by those skilledA in the art without departing from the spirity and scope of the invention as expressed in the appended claims.

Referring to the drawings:

Figure l. is a fragmentary side elevational view of a honing machine embodying the features of the invention.

Fig. 2 is a transverse sectional view taken along erna machine selected to illustrate the invention is of the verticalvtype .having vaframe structure including a column head or housing 1 mountedon thetop of an upright column 8. Preferably, the head l is in the form of a. unitary, hollow casting of generally rectangular cross section and is provided with a forwardly projecting portion'in overhanging relation to the side of the column il. lin the preferred form, the various operating and control elements of the machine are enclosed incr supported by the head which materially simplifies manufacture of the machine.

The operating elements of the machine include a tool carrying member in the form of a rotatable and reciprocable spindle 94 for carrying the tool into operative engagement with the work, which latter may be supported in any suitable manner adjacent the side of the column 8. The tool spindle 9 is supported in the overhanging portion of the head for reciprocation in a of the reciprocating parts to a minimum, the tool spindle itself is extended .axially through the cylinder and is provided with a. piston ifi operaable in the cylinder. Pressure fluid is introduced into opposite ends of the cylinder alternately through suitable ducts iii (Fig. 1) com-r municating respectively with the upper andlower ends thereof.

In the preferred form of the machine, the cylinder itl is cest integrally with the head l and is held rigid therewith by a web l joining the upper end of the cylinder and the side walls of the head as shown in Fig. 3. Preferably, the cylinder terminates substantially below the top wall of the head leaving sucient space therein for the spindle rotating mechanism and, control instrumentaiities which cooperate with the projecting upper end of the tool spindle. The ends of the cylinder are closed by suitable cylinder heads il and it which also provide sliding bearing supports for the tool spindle. As herein shown, the cylinder' head il is threaded into the upper end of the cylinder and cylinder head iii is bolted or otherwise secured to the lower end thereof.

spindle head or carriage heretofore required is entirely dispensed with and only the tool spindle 9 and the tool itself are reciprocated.` The weight of the reciprocating parts of the machine is thus reduced to a minimum permitting the use of simpler and less expensive construction without sacrice of durability or accuracy. Moreover, the number of parts required for the machine is materially reduced with corresponding reductions in the cost of manufacturing the same.

Pressure uid for reciprocating the .tool spindle 9 may be derived from any suitable source such as a pump 20 which, as herein shown, is directly coupled with the-drive shaft 26* of the motor H. I'he pump 2B' has the usual intake duct 2l for drawing iluid from a storage reservoir or sump 2l* which, for convenience, may be enclosed within the head l. Fluid under pressure is discharged through a pressure duct 22 leading to To simplify the construction ofthe machine and to reduce the weight areversing valve 23 which directs the iluid alternately to the upper and lower ends of the cylinder i3. Any suitable type of reversing valve may be employed such as the rocking type valve illustrated in Figs. l and 2 which has valve stem 2lI operable to reverse the pressure lln'e connections when rocked through a relatively small angle. Operation of the reversing valve is effected automatically by control mechanism to be described hereinafter. Y

The mechanism for rotating the tool spindle l comprises, in the present instance, a drive shaft 25 supported in a substantially horizontal position adjacent the upper end of the head 1 in suitable bearings 26 and 21 with one end of the shaft projecting rearwardly of the head. 'Ihe shaft has a suitable driving connection with the motor il, as, for example, a IV-belt 28 operating over pulleys 29 and 310 caned on the .projecting end of the shaft 25 and the motor shaft 20, respectively. To provide for rotating the tool spindle at different speeds, the pulleys 29 and 36 may conveniently be vof the stepped cone type. If additional speed changes are required, the pulleys may be readily interchanged with others of the desired ratio.

Fast on the inner end of the shaft 25 is a bevel gear 3i meshing with a crown gear 32 having a splined driving connection with the tool spindle il. The crown gear is alined axially with the spindle and Vis journaled in a bearing -il formed in or suitably secured to the top wall of the head 7l. Thus, the spindle may reciprocate freely relative to the crown gear while being rotated thereby, the spliced portion of the spindle being of sucient length to main tain the driving connection throughout the entire stroke. To protect the bearing. suriaces from dust or grit, the projecting end of the spindle is enclosed in an elongated, hollow guard 35 mounted on the top of the housing.

' Suitable means is provided for engaging and disengaging the driving shaft 2S and the motor li so that the rotation of the tool spindle may be interrupted without necessitating stopping of the motor. As herein shown, this means is in the forni of a belt tensioning device and includes a roller 5 carried by an arm 3l pivotally mounted on the rear wall of the head l. The roller is disposed intermediate the pulleys 2li and 38 and in a position to place the belt 2t under tension when the free end of the arm 3l is moved downwardly from its normal position.

Movement of the arm 3l to engaging or disengaging positions is effected through the medium of a horizontally disposed rock shaft 23 supported at one side of the housing l in front and rear bearings 38 and 38'. A crank 39 fast on the rear end of the shaft is operatively connected with they free end of the arm 31 by a pin 4 6 operating in a suitably formed slot in the arm whereby movement of the shaft is transmitted to the arm. At the other end of the rock shaft 33 is a crank arm 4l from which depends a manual actuating lever 42 by which the shaft may be conveniently rocked to engage or disengage the drive mechanism. A coiled spring 4I* encircling Vthe shaft and interposed between the bearing 3Sa and a collar 4|* fast on the shaft.

urges crank 39 into engagement with the end of the bearing and thus tends to fricticnally maintain the shaft 'and tensioning device in either set-position.

The control mechanism for operating the reversing valve 23 to control the reciprocating cycle of the machine is of simple and rugged construction and, by reason of the improved combination and arrangement of the parts, is susceptible of extremely accurate adjustment'. Referring to Figs. 2 and 3, the control mechanism includes a ,control rod disposed at one side of and subthe stop 46 to define the limits of the working stroke of the spindle.

To provide for the accurate positioning essential fork precision honing, the stops 45, and il'l are threaded onto the control rod. Suitable means are provided for locking the Jstops in set position to prevent accidental displacement. Stop d, which denes the extreme upper limit of thev spindle stroke, will ordinarily require adjustment only to compensate for wear of the cooperating parts and the locking means for this stop may conveniently take the form of a locking screw 43. Stops 4B and 41, however, define the working stroke of the spindle and will require adjustment whenever the class of work operated on by the machine is changed. To facilitate such adjustment, the locking means for these stops preferably comprises locking nuts 49 and 50 threaded onto the control rod adjacent the respective stops. Thus the stops 46 and 41 may be quickly and easily adjusted and locked in place to define precisely the working stroke required for a particular class of work.

As herein shown, (Fig. 3) the stops45, 46 and 41 are generally disk shaped in form and are positioned for engagement byvan actuator 5l carried by the tool spindle 9 and reciprocable I therewith. In the preferred form, the actuator 5I comprises a hollow cylindrical member rotatably supported by anti-friction bearings 53 on a collar 54, the member being counterbored at each end to receive the bearing race rings. The collar 54 is mounted on a reduced portion of the spindle and is clamped against a shoulder 55 formed thereby through the medium of a nut 56 threaded onto the spindle which holds the collar rigid with the shaft. Thus, while the tool spindle and collar are rotating, the actuator remains stationary for engagement with the stops on the control rod. Endwise movement of the actuator 5I relative to the collar 54 is effectually prevented by employing bearings of the preloaded type, thus eliminating all endwise play of the actuator.

To enable the actuator El to pass the intermediate stop il when the tool spindle 9 is advanced from its withdrawn or starting position to working position, the actuator is provided with a longitudinally extending cam groove 51 (Fig. 2) on the side adjacent the control rod 43. One wall of the cam groove, in the present instance the left hand `wall as viewed in Fig. 4, is sub-,-

stantially parallel to the axis of the actuator, while the other wall is inclined relative thereto so-that the upper "end of the groove is of just silcient width to permit the actuator to pass the stop when it is rotated to a predetermined passing position and the lower end of the groove is of sulcient width to receive the stop when the actuator is in eitherits passing position or its normal position.` Thus when the spindle is initially advanced from starting position, the stop 41 ls engaged by the bottom portion of the cam groove and the actuator is enabled to pass'the intermediate stop 41 wit-hout shifting the control rod. In passing. of course, the actuator is ro-r tated to its passing position by the cam action of the stop but is immediately and automatically returned to normal position as will appear presently. f p

` After stop 41 is passed. the advance of the tool spindle continues until the actuator engages the limit stop 46 to shift the control rod 43 and operate the reversing valve 23. The spindle is then moved upwardly until the actuator engages the intermediate stop 41 which it will do by reason of the fact that it is in. normal position with the upper end of the cam groove 51 out oi' alignment with the stop. The tool spindle will thus be reciprocated in its working stroke as determined by the positioning of the stops 46 and 41, which enable the actuator carried by the spindle to shift the control rod at each end of the stroke. To terminate the working stroke of the spindle and return it to the withdrawn position, the actuator 5l is rotated to a position in which the upper end of the cam groove is aligned with the stop 41. The. spindle thus continues its upward movement until the actuator engages the upper limit stop 45 and thereby operates suitable control mechanism eiective to stop the machine.

Movement of the actuator 5I from normal to .passing position is effected by suitable control means enclosed in the head 1. To this end, the side of the actuator opposite the cam groove 51 is formed with longitudinally extending teeth 58 adapted to mesh with the teeth of a segmental gear 59 is of substantial length so as to con-v stantly mesh with the actuator as the latter reciprocates with the tool spindle. Thus, the actuator is under control of the gear 59 at all times.

As' will beseen by reference to Fig. 3, the segmental gear 59 is fast on a vertical shaft 60 rotatably supported in spaced bearings formed in brackets 5I on the side of the wall of the head 1. The shaft and gear are held in a normal position by means of a coiled spring 62 encircling the shaftfone end of the spring being anchored toa collar 53 pinned to the shaft, the other end being anchored to a sleeve B3 loosely mounted on the shaft but held against rotation relative thereto by a pin 94 (Fig. 2) threading into the front wall of the head ahd engaging one of the several apertures provided in the sleeve for this purpose. The tension of the spring 52 may be readily adjusted by withdrawing the pin 64 from engagement with the sleeve and rotating the sleeve until the desired tension is obtained, whereupon the sleeve is locked in place 'in the usual way. A second collar 65 fast on the shaft holds the sleeve in position when the pin 64 is temporarily withdrawn from engagement therewith and also prevents the sleeve from binding crank arm 69 fast on they lower end of the shaft.

ing the movements of the tool spindle to prevent `on the side wall of the head 1.

The solenoid 6.6, on being energized, draws in the armature 61 and thus rotates thev shaft `|0 and gear 58 in a clockwise direction as viewed in Fig. 2. 'Ihe actuator 5| is thereby rotated in the opposite direction to the passing position in` which the cam slot 51 is aligned with the intermediate stop 41. When the solenoid becomes deenergized, the shaft, segmental gear and actuator are returned to the positions shown in Fig. 2, that is, their normal positions, under the influence of the spring 62.

The engagement of the actuator 5| with the upper limit stop 45 or the intermediate stop 41 shifts the control rod 43 from its lower to its I upper'position. In order to maintain the control rod in this position during the downward stroke of the tool spindle, means is provided for .substantially counterbalancing the weight of the rod. As herein` shown, the counterbalancing means'comprises a compression spring 52 (Fig. 3) encircling the control rod and interposed between the lower bearing of the rod and a collar 53l fast on the rod.

It will be observed that, with the above construction, the control rod 43 is movable only endwise, and that the actuator 5| mounted directly on the spindle is rotated to provide the skipstop action by which the tool spindle is moved to and from the operating position. 'I'his is an important feature of the invention as it permits the use of simple, rugged stops which can be threaded onto the control rod to provide for precision adjustment of the spindle stroke. It also results in a simplification of the associated parts and apparatus and permits the control rod to serve the additional function of positively limitoverrun at the ends of the working stroke as will be described in detail hereinafter. The Ashifting of the control rod 43 is utilized to operate the reversing valve 23 and thereby control the reciprocationof the spindle. To this end, the control rod is formed with rack teeth 10 (Fig. 3), engaging with a pinion 10a (Fig. 2) i fast on the end of a cross shaft 1|, which is journaled in an elongated bearing 1| formed The shaft 1| carries a crank arm 12 connected by alink 12EL with a second crank arm 13 fast on the rocking valve stem .24. Thus, when the cross shaft is rocked` incident to the shifting ofthe control rod by the spindle carried actuator, the valve stem' is moved from one position to the other to direct pressure fluid to the upper and lower ends of the cylinder |3V alternately.

Due to inherent operating characteristics of` i the hydraulic mechanism, it is impractical to obtain absolutely uniform stroking of the tool spindle by means of the reversing .valve alone, the spindle ordinarily overrunning somewhat at each end of the stroke. This overrun affectsv the accuracy of the work and hence, is objectionable in precision honing. -To avoid this difculty. suitable means is provided for positively stopping the movements of the tool spindle exactly at the prescribed limits of its less of the length of thestroke. i

In its preferred form,the stop means 'comprises suitable stop members or bumpers 14 and 15 stationarily supported in the head 1 and positionedv for engagement by the upper limit stop 45 and the collar 53a respectively, as the control rod 43 is shifted -up or down by the actuator 5| engaging the stops 46 and 41, and coincidentally with working stroke, regardthe tool spindle reaching the limits of its stroke. The bumpers 14 and 15 are preferably constructed of hard rubber or other resilient material to enable them to absorb the shock incident to stopping the tool spindle and to render the machine quiet in operation. Thus, movement of the control rod and the tool spindle is positively Astopped with a minimum of shock and jar, and overrunof the spindle is effectually prevented, vthereby enabing the machine to operate with the accuracy essential for precision honing.

'Ihe movement of the cross shaft 1| is further y utilized to operate an electric stroke counter 11, preferably of the type disclosed in my prior Patent No. 1,945,045, grantedl January 30, 1934. As herein shown, (Fig. 1), the stroke counter is mounted on the front wall of the head 1 with its operating arm 18 extending generally rearwardly toward the cross shaft. A 4crank arm 18 fast on the cross shaft is arranged to operatively engage the operating arm 18 incident' y counter incident to the return of thetool spindle to starting position at the end of an operating cycle. As herein shown, (Figs. l and 2) this means includes a stop bar 8| extending generally lparallel to the axis of movement of the tool spindle and slidablysupported for endwise move- `ment by brackets 82 and 83 on the front wall of the head. An operating arm 84 fast on the bar projects rearwardly therefrom and into the head through a slot 85 provided for this purpose. The arm 8 4 is positioned so as to rest on the actuator 5| when the tool spindle is in the startingor withdrawn position thereby supporting the weight of the bar. When the spindle is advanced to working position the support for the bar is lwithdrawn and the bar moves under its own weight. downwardly until a stop collar 86 carried bythe bar engages the bracket 83. 'I'he stop bar remains in its lower position throughout the operating cycle of the machine.4

The stopping of the machine is effected by the stop bar through the medium of a switch 81 (Figs. 1, 2 and 6) arranged, when operated, to interrupt the energizing circuit of a solenoid 88 which controls a main switch 89 through which current is vsupplied to the motor To this end, the bar carries an actuating member 98 arranged to cooperate with a switch arm 9| by which the switch 81 is actuated, the arrangement being such that the switch is opened when the bar isv in its upper position and closed when in'its lower position. Resetting of the stroke counter 11 is efi fected by the movement of the stop bar from the lower to the upper position throughv the medium `of a rack 92 on the bar engaging with a reset- :sor

n rod to its upper or'lower switch is closed in response to the energizstiolr.v

arranged for operating the reversing valve 23 independently of the automatic control mechanism hereinbefore described.

Referring more particularly to Figs. 2 and 5, the manually operable short stroking means. in

vlll its preferred form comprises a pair of sleeve members @d and 95 arranged end-to-end and yieldably coupled by a coiled spring 9S encircling and anchored at opposite ends to the respective members. The coupled sleeves are loosely mounted on` is the cross-shaft il, a limitcdslidng movement axially ofthe shaft being permitted by the positioning oi a retaining collar 9i fast on' the end of the shaft. The iz'nember @il is provided on its inner face with a clutch element es adapted to 2o vengage a complementary clutch l element formed on the hub oi the' crank arm 'l2 which, as previously explained, is fast on the shaft li. A-hand lever tu@ secured to thevmember @d provides a convenient means of rotating the cou 2c pled members.

it will be apparent that, when the clutch elements 93 and Q9 are engaged, the reversing valve 23 may be operated to either of its positions by manipulation of the hand lever lil@ thus permit- :lo ting the attendant to control the stroke of the tool at any .point in the' work. When it is desired to short stroke at a point intermediate the ends of the normal working stroke, the clutch is engaged and the hand lever it@ is osclllated to g5 reverse the valve 23 at the proper intervals. For

short stroling in areas` adjacent the ends oi the normal working stroke, the clutch elements are engaged and a steady pressure is applied to the hand lever it@ tending to move the control position as required. Thus iorshort strokingl at the lower end of the normal stroke the handlever is forced 'to the rightl as viewed .in raise the control rod'to its upper position and operate the valve 23 so that pressure fluid is vsupplied. to the upper end of the cylinder i3 before the spindle reaches the upper limito! its VWorking stroke. The hand lever is turned in the' other direction to short stroke" at the upper .end of the normal stroke, valve 2t being operated to introduce pressure-duid into the operating cylinder before the spindle reaches the lower limit oi its stroke. The amount of pressurefapplled tothe hand lever determines the short stroking cycle by regulating the tension of the spring 9B througnwhich the control rod sluiting 'torce is applied. Moreover, by reason ot vthe yieldable connection oi the clutch sleeve 8l and lever sleeve 95, the shock resulting from the et" engagement of the actuator sl with the limit stops as the spindle moves toward its normal limit position is absorbed by the spring 98 instead of being transmitted tothe handlever |00.

The lattendant is thus enabled to control the short stroking operation easily and with greater Referring new to Fig. 6,1the' electrical control system oi the machine is'especially arranged with a view to simplifying the work oi the attendant 7o' and, at the same time, providing eihcient and reis motor il through a main switch 89 when Vthe Fig. 1, thereby tending toL of the solenoid 88. The solenoid is initially energized to start an operating cycle of the ma.- chine (by the momentary closure of a push button operated starting switch |02.

To .continue the operation of the machine through a complete cycle comprising, for example, an approach stroke wherein the tool spindle is advanced from starting to operating or work,- ing position, a plurality of working strokes, and a. return stroke to withdraw the spin dle toQstarting position, means is provided for maintaining the solenoid 88 energized under contiel of the stroke counter Tl.

. To this end, the solenoid is provided with a holding circuitincluding normally closed push button switches l and Illt, the stop switch 81,

closed when the tool spindle is advanced from the starting position, and a switch lod closed bythe solenoid 8B concurrently with the closure oi the main switch B9. In the normal operation of the machine, stroking ory the tool spindle continues4 .I

until the solenoid SS' is energized under control of the stroke counteril to permit the spindle to return to starting position and'open the switch di.' Upon the opening of the switch d?, solenoid d8 becomes deenergized and opens the main switch B9 thereby stopping the motor ii.

In case of emergencies, the motor il maybe .stopped independently of the stroke counter by.

the actuation of the stop switch lii. This opens the solenoid holding circuit with the same results as the opening of the switch di.

When setting up the work and when nrst Aadvancing the tool into engagement therewith, it is desirable to advance the tool spindle in relatively short stem without initiating an operatingcycle of the machine,` this operationbeing commonly referred to as inching. With this in view.' an inching push button has been provided for opening the normally closed switch |04 and simultaneously closing a normally open switch |06.' 'Closure of the switch |08 energizes the solenoid 88 to start the motor in the usual way. Locking up of the solenoid is prevented, however, by reason oi' the opening of switch |04 which prevents the completion of the holding circuit. Thus, the motor is operated and the tool spindle is advanced only while the lnching" push button is actuated. the operation ceasing as soon as the push button is released. The attendant is thus enabled to vadvance the tool .into the work in easy stages.

The control system counting apparatus is set to increase or decrease the number oi working strokes oi the tool. As will be seen by reference to the drawings, the switch 80 of the stroke counter, when closed, completes a circuit through a. normally closed :switch |01, for energizing an auxiliary solenoid |38. Solenoid |08 in turn closes a switch |09 to complete an energizing circuit for the solenoid t6 which actuates the control mechanism to terminate the operation of the machine with the tool spindle 'withdrawn to starting position. Since the switch |01' is in series with the switch d0, opening of the first mentioned switch will prevent the energization oi.' the solenoid lill and thus increase the number oi strokes over the number set on the counter. A normally open switch is connected in parallel with the counter switch- 80, so that when'a smaller -numberiof strokes also includes means ior` varying the stroking cycle for whichthe stroke is desired than the number set up on the counter,

energization of the solenoids |08 and 66 may be effected independently of the counter switch.

It will be apparent from the foregoing description that the invention provides a honing 'ma- 'chine of improved and simplified construction which is relatively inexpensive to manufacture. The weight of the reciprocating parts is reduced to a minimum thereby materially improving the Moreover, the control mechanism has been improved to provide for precision adjustment and, at the same time, to obtain a simple and rugged construction which is eiiicient and reliable in operation.

y I claim as my invention:

1. In a honing machine having a rotatable and reciprocable tool carrying spindle,y in combination with a frame structure, an elongated cylinder supported on said frame structure coaxially with the spindle, said spindle extending entirely through the cylinder and having sliding bearingsupports at opposite ends thereof, a piston element on the spindle within said cylinder, means for reciprocating the spindle including a source of pressure fluid and valve means for directing the pressure iiuid linto opposite ends of said cylinder alternately, and an actuator carried by said spindle above the piston element cooperating with control means on said frame structure for actuating said valve means.

2. In a honing machine having a rotatable and reciprocable tool carrying spindle, in combination, means for rotating the spindle, hydraulic means for rapidly reciprocating the spindle simultaneously with its rotation, valve means for controlling said hydraulic means and operative to determine the approximate limits of movement of the spindie, and control mechanism for actuating said valve means and operative to terminate the movements of the spindle exactly at the prescribed limits of its movements, said control mechanism including an actuating member mounted on the spindle for reciprocation therewith,.a control rod slidably supported for endwlse movement at one side of the spindle, a pair of spaced elements mounted on said control rod in position respectively to be operatively engaged by said actuatingv member as the spindle approaches the limits` of its movement whereby the control rod is shifted in the direction of movement of the spindle, means operated by the control rod in its movement for actuating said valve means, and means engageable with said control rod upon the spindle reaching the prescribed limits Aof its movements for positively stopping the spindle.

3. In a honing machine, in combination, a rotatable and reciprocable tool carrying spindle, means for rotating the spindle, means for rapidly reciprocating the spindle simultaneously with its rotation, and controlling means for said reciprocating means operative to conilne the reciprocating movements oi the spindle within accurately dened limits, said controlling means including an actuating member mountd on the spindle, a rod slidably supported for endwlse movement substantially parallel to the path of movement of the spindle, a pair oi' spaced elements mounted on said rod in position respectively to be engaged by said actuating member as the spindle approaches the limits oi' its movement whereby the rod is shifted in the direction of movement of the spindle, and stop means coacting with said rod to positively stop the spindle exactly at its prescribed limits of movement.

ciprocatory tool carrying spindle having a working stroke of substantially shorter length than the maximum stroke of the spindle, hydraulic means for rapidly reciprocating said spindle in its working stroke, and control means eiective to control said hydraulic means and to positively prevent the spindle ,from overrunning the limits of its working stroke,- said control means including a member adapted to be shifted alternately in opposite directions by said spindle as the spindle approaches the limits of its working stroke, and resilient means engageable by said member incident to its shifting for stopping spindle movement exactly at the prescribed limits oi the working stroke and for absorbing the shock incident tov such stopping.

5. Control mechanism for a honing machine having a reciprocatory tool carryingspindle comprising, in combination, an lactuating member carried by the spindle and reciprocable therewith, a control rod supported for endwise movement parallel to the axis of movement of the spindle, a pair of limit stops mounted on said rod in spaced relation, said stops being positionedon opposite lsides of said actuating member and alternately engageable thereby to dene the extreme limits 4. In a honing machine, in combination. a re-A of spindle movement, an intermediatestop mounted on said 4rod between said'limit stops and engageable by said actuating member to define with one of said limit stops the working stroke oi.' the spindle, said inter-mediate stop and one o! said limit stops having threaded connections with said rod whereby precision adjustment oi' the stops relative to each other and to said actuatingmember may be effected, and means for shifting said actuating member relative to the spindle to enable vthe member to pass saidintermediate Istop withl out operatively engaging the same.

6. Acontrol mechanism for a machine tool hav- I ing 'a reciprocating tool carrying spindle, comprising, in combination, a control element supported for movement parallel to the axis of movement of the spindle, a pair oi' limit stopsmounted on said element in spaced relation. an intermediate stop' mounted on said element between said limit stops, an actuator carried by said spin dle adapted. to coact with said stops to shift said element and thereby control the reciprocation oi the spindle, said actuator including a'member movment of the spindle;a pair of limit stops mounty ed onsaid elementin spaced relation, an interw mediate stop mounted on said element between said limit stop.` and an actuator carried by said spindle adapted to coact with said stops to shift the control element and thereby control the 1reciprocation of the spindle, said 'actuator being eiiective to operatively engage the intermediate stop when the spindle is moving in one direction ciated with said controLrod for controlling the.

reciprocation of the spindle, a pair of limit stops mounted on said rod in spaced relation, and an actuator mounted directly on said spindle and reciprocable therewith positioned to coact with.. said stops in the reciprocation of the spindle tg' actuate said control rod.

9. A control mechanism for a machine tool having a reciprocating to'ol carrying spindle comprising, in combination, a control rod supported for movement parallel to the axis of movement of said spindle, a pair of limit stops mounted on said 'rod in spaced relation, an intermediate stop mounted on said rod between said limit stops, and

an actuator carried by said spindle operative toengage said stops to shift the control rod and thereby control the reciprocation of the spindle, said actuator being movable relative to the spindle to a position in which it is ineffective to engage said intermediate stop.

l0. A control mechanism for a machine tool having a reciprocating tool carrying spindle comprising, in combination, a control rod supported. for movement parallel to the `axis of movement of said spindle, a pair of limit stops mounted on said rod in spaced relation, an intermediate stop mounted on said rod between said limit stops, and an actuator carried by the spindle and reciprocable therewith operative to engage said stops to shift the control rod and thereby control the reciprocation of the spindle, said actuator comprising a cylindrical member encircling the spindle and rotatable relative thereto to one ps'ition in which the actuator is effective to operl atively engage said intermediate stop and to another position in which the actuator is ineective to operatively engage lsaid intermediate stop.

11. A control mechanism for a machine tool having a reciprocating tool carrying spindle comprising, in combination, 'a control rod supported for movement parallel to the axis of movement of usaid spindle, a pair 'of limit stops mounted on said rod in spaced relation, an intermediate stop mounted on said rod between said limit stops, and an actuator carried by the spindle and reciprocable therewith operative to engage said stops to shift the control rod and-thereby control the reciprocation of the spindle, said actuator comprising a cylindrical member encircling the spindle and rotatable relative thereto to one position in which the actuator is effective to oper*- atively engage said intermediate stop and to another position in which the actuator is ineiective to operatively engage said intermediate stop, and means cooperating with said member in all `positions of the reciprocating spindle operable selectively vto rotate said member to. either position.

12. A control mechanism for a machine-tool having a reciprocating tool carrying spindle com-4 prlsing, in combination, a control rod supported for movement parallel to the axis of movement of said spindle, a pair of limit stops mounted on said rod in spaced relation, an intermediate stop mounted on said rod between said limit stops, and an actuator carried by the spindle and reciprocable therewith operative to engage said spindle operative to maintain the member in said :l`

'one position.

13. A control mechanism/for a machine tool having a rotating and reciprocating tool carrying' spindle comprising, in combination, a control rod supported for movement parallel to the axis of movement of the spindle, a pair of limit stops mounted on said rod in spaced relation, an intermediate stop mounted.v on said rodA between said limit stops, an actuator carried by the spindle operative to engage said stops to shift the control rod and thereby control the reciprocation of the spindle, said actuator comprising a cylindrical member rotatably supported on the spindle' and reciprocable therewith, and means'for holding said member against rotation with the spindle to render the actuator effective to engage said intermedi/ate stop andv one of said limit stops alternately whereby the spindle is` reciprocated through a series of working strokes.

i4. In a'honing machine, in combination, a

tool carrying member, hydraulic means for reciprocatng said member, valve means forcontrolling said reciprocating means, control means for said valve including a rock shaft adapted to be automatically actuated 4incident to said' spindle approaching the limit of its stroke, and means for modifying the action of said control means to shorten the stroke of said spindle comprising a manually operable member loosely mounted on said shaft, and disengageable clutch means op eratively connecting said member with said shaft 'whereby said member is enabled to actuate said shaft.

15. 'In a honing machine, in combination, a tool carrying member, hydraulic means for reciprocating said member, valve means for controlling said reciprocating means, control meansfor said valve including a rock shaft adapted to be automatically actuated incident to said spindle approaching the limit of its stroke, and meansfor modifying` the action'of said control means to shorten the stroke of said spindle comprising a member loosely mounted on said shaft and hav-1 ing a disengageable operative connection' with. the shaft, la second member loosely mounted on said shaft adjacent said ilrst member, manually operable means for rotating said second member relative to the shait,'and means yieldably connecting said members for transmitting the rotational movement of said second member to said shaft to actuate the same, said connecting means absorbing the shock incident to the automatic actuation of the shaft.

16. a holding machine, in combination, a

tool carrying member, means for reciprocating L; said member, control means for said reciprocating means including acontrol rod movable be tween two control positions, spaced stop ele ments mounted on said rod, an actuating member carried by said member operative to engage said stop elements and-thereby shift the control rod from one position to the other alternatively incident toi thel reciprocation of said member.,

and means for shifting said control rod from one 'lasH having a reciprocating part comprising, in combination, a control rod supported for movement parallel to the reciprocatory path of said part, a pair of limit stops spaced longitudinally o! said rod, an intermediate stop interposed between said limit stops, a-two-position actuator carried by said reciprocating part, said actuator being effective in one position to operatively engage either said intermediate stop or said limit stops and effective in the other position to engage only said limit stops to actuate the control rod, and means for shifting said actuator from one position to the other.

18. A control mechanism for a machine tool having a reciprocating part comprising, in combination, a movable control element supported adjacent said part, a pair of limit stops adjustably mounted on said element in spaced relation, an intermediate stop adjustably mounted on' said element between said limit stops. a two-position actuator carried by said part and reciprocable therewith, said actuator being operative in one position to engage either said limit stops or said intermediate stop and in the other position to engage only said limit stops to actuate the con- Y trol element, and non-reciprocating means for moving said actuator from one position to the other while said part is reciprocating. l

19. In a honing machine, in combination, a tool support, a work support, means for reciprocatingA one of said supports relative to the other support to cause the tool to operate upon the work, control means for said reciprocation means including a solenoid adapted when energized to render said reciprocating means operative to reciprocate said one support and adapted when deenergized to interrupt the operation of the reciprocating means,

rst and second energizing circuits for said solenoid, a holding circuit for the solenoid, a manually operable switch eiective when actuated to complete said ilrst energizing circuit to energize whereby to effect operation of said reciprocating' means only while the secondvswitch is actuated. 20. In a honing machine, in combination, a tool support,a work'support, hydraulically operated .means for moving one oi' said supports toward and from the other support to cause the tool to operate upon the work, a source of pressure iluid, control means including a solenoid adapted when energized for rendering said source effective to supply pressure iluid to said hydraulic means for moving said one support and adapted when deenergized to interrupt the supply of pressure iluid to said hydraulic means to stop the support, rst and second energizing circuits for said solenoid, a holding circuit for the solenoid, a manually operable switch in said first energizing circuit operative when actuated to energize said solenoid and thereby initiate the operation o! said hydraulic means, a switch in said holding circuit 'operable on energization of said solenoid to hold the solenoid energized and thereby continue operation of said hydraulic means independently of said manually operable switch, and. a second manually operable switch in said second energizing circuit operative when actuated to energize the solenoid and to disable said holding circuit to eiIect opersecond switch is actuated.

ALBERT M. JOHNSON. 

